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Microbial Spoilage of Bakery Products and Its Control by Preservatives



Spoiled food may be defined as a food that has been damaged or injured so as to make it undesirable for human consumption. Bakery products are an important part of a balanced diet and a wide variety of such products can be found on supermarket shelves. However, bakery products, like many processed foods, are subject to physical, chemical and microbiological spoilage. While physical and chemical spoilage limits the shelf life of low and intermediate moisture bakery products, microbiological spoilage by bacteria, yeast and molds is the concern in high moisture products. Many industrially produced baked goods emerge from the baking process with a surface that is essentially sterile but post bake handling can quickly lead to fungal, microbial surface contamination as a result of exposure to airborne contaminants as well as equipment contact. This present review is focused on the microbial spoilage of bakery products and its control by preservatives. This review assesses the following topics: economical importance of bakery products, microbial spoilage of bakery products, physical factors affecting microbial growth, control of microbial growth in bakery products by using chemical preservatives and biopreservatives.
*Corresponding Author: P.Saranraj, Email:, Phone No: +91- 9994146964
ISSN 0976 3333
Available Online at
International Journal of Pharmaceutical & Biological Archives 2012; 3(1):38-48
Microbial Spoilage of Bakery Products and Its Control by Preservatives
P.Saranraj* and M.Geetha
Department of Microbiology, Annamalai University, Annamalai Nagar, Chidambaram608 002
Received 11 Sep 2011; Revised 08 Dec 2011; Accepted 13 Dec 2011
Spoiled food may be defined as a food that has been damaged or injured so as to make it undesirable for
human consumption. Bakery products are an important part of a balanced diet and a wide variety of such
products can be found on supermarket shelves. However, bakery products, like many processed foods,
are subject to physical, chemical and microbiological spoilage. While physical and chemical spoilage
limits the shelf life of low and intermediate moisture bakery products, microbiological spoilage by
bacteria, yeast and molds is the concern in high moisture products. Many industrially produced baked
goods emerge from the baking process with a surface that is essentially sterile but post bake handling can
quickly lead to fungal, microbial surface contamination as a result of exposure to airborne contaminants
as well as equipment contact. This present review is focused on the microbial spoilage of bakery products
and its control by preservatives.
This review assesses the following topics: economical importance of
bakery products, microbial spoilage of bakery products, physical factors affecting microbial growth,
control of microbial growth in bakery products by using chemical preservatives and biopreservatives.
Key words: Bakery products, Microbial spoilage, Bacteria, Fungi and Preservatives.
Bakery products are the important staple foods in
most country and cultures. Bakery products and
cereals are a valuable source of nutrients in our diet
providing us with most of our food calories and
approximately half of our protein requirements.
Cereals have been a basic food of man since
prehistoric times and were consumed long before
bread making was developed. Variety breads and
other bakery products have increased in sales
volume within the past decades. The nutrients in
bakery products are carbohydrates, proteins, lipids,
vitamins and minerals. Bakery industry in India is
the largest of the food industries with an annual
turnover of about B 3000 crores. India is the second
largest producer of biscuits after USA. The biscuit
industry in India comprises of organized and
unorganised sectors. Breads and biscuits form the
major baked foods accounting for over 80 per cent
of total bakery products produced in the country.
The quantities of bread and biscuits produced are
more or less the same.
Bakery products once considered as sick man’s
diet have now become essential food items of the
vast majority of population. Though bakery
industry in India has been in existence since long,
real fillip came only in the later part of 20th
century. The contributing factors were
urbanization, resulting in increased demand for
ready to eat products at reasonable costs etc.
Importance of bakery products has expanded
especially the use of whole and natural grains and
other natural ingredients. Furthermore, bakery
products are considered as a source of
carbohydrates because starch is the main chemical
constituent [1]
Commercially produced and properly handled bread
generally lacks sufficient amounts of moisture to
slow growth of any microorganisms except moulds.
As normal cooking temperature destroy fungal
spores, post-process contamination from airborne
spores and contact with contamination surfaces must
be prevented. Filamentous fungi involved in
spoilage of bread include Rhizopus sp., and Mucor
sp., Penicillium sp., Eurotium sp., Aspergillus sp.
and Monilia sitophilia. One of the most common is
. Bakery products are subjected to
spoilage problems. These include physical,
chemical and microbial spoilage. Since the most
common factor of bakery products is water
activity, microbiological spoilage, in particular
mould growth is the major economical importance
of bakery products. Mould spoilage is a serious
and costly problem for bakeries.
P.Saranraj et al. / Microbial Spoilage of Bakery Products and Its Control by Preservatives
© 2010, IJPBA. All Rights Reserved.
Rhizopus stolonifer, often referred to as the ‘bread
mould’. Storage of bread under conditions of low
humidity retards mould growth. In addition to the
economic losses associated with bakery products,
another concern is the possibility of mycotoxins
production. Eurotium species are usually the first
fungi to colonize improperly water allowing other
species. Aspergillus and Penicillium which can
produce toxins to thrive. Losses of bakery products
due to mould spoilage vary between 1-5 per cent
depending on seasons, type of products and methods
of processing.
Members of the genus Bacillus bring about
bacterial spoilage of bread known as rope. This is
of major economic to the baking industry.
Ropiness which is the most important spoilage of
bread after moldiness occurs particularly in
summer when the climatic conditions favour
growth of bacteria. It is mainly caused by Bacillus
subtilis but Bacillus licheniformis, Bacillus
magaterium and Bacillus cereus have also been
associated with ropy bread. The incidence of
wheat bread spoilage caused by Bacillus has
increased during the last few years presumably
because more bread is produced without
preservatives and often raw materials such as bran
and seeds are added. Spoilage of bread by rope
formation may constitute a health risk, high
numbers of Bacillus subtilis and Bacillus
licheniformis in foods may cause a mild form of
food illness. Consumption of ropy bread has been
association with food-borne illness in reports from
Canada and the United Kingdom.
The stability of bakery products against the attack
by fungi is mainly due to preservatives.
Preservatives help to reduce or prevent wastage of
food through spoilage caused by microorganisms.
Longer shelf life enables a greater variety of
products to be kept in store and in the home. Sofos
and Busta (1991)[2] reported that chemical
preservatives can control the growth of molds by
preventing the metabolism, by denaturing the
protein of the cell, or by causing physical damage
to the cell membrane. Among these preservatives
are propionic and sorbic acid or their salts which
have been show to increase the shelf life of bakery
products. Propionic acid and calcium propionate
are usually employed at concentrations of 0.1 and
0.2 per cent respectively. At these levels, moulds
can be inhibited for 2 days or more and the
formation of rope can be prevented [3]
Problems due to spoilage yeasts in bread usually
result from post-baking contamination, slicing
machines, bread coolers, conveyor belts and racks
have been identified as sources. Yeast spoilage is
characterized by visible growth on the surface of
products. The most frequent and troublesome
yeast is Pichia butonii, which is known as “chalk
mould”. This yeast can multiply rapidly on bread,
with visible growth often apparent some time
before mould occurs. Filamentous fungi are more
common than yeast on British breads. Since,
filamentous fungi are more easily recognized than
yeast, because they generate the majority of
complaints. The stability of bakery products
against the attack by fungi is mainly due to
preservatives. Preservatives help to reduce or
prevent wastage of food through spoilage caused
by microorganisms. Longer shelf life enables a
greater variety of products to be kept in store and
in the home.
Bakery products are an important source of
nutrients viz., energy, protein, iron, calcium and
several vitamins. Commercial bread and biscuits
contain around 7.5 per cent to 7.8 per cent protein
respectively. Bakery products are good targets for
fiber enrichment, as the decline of fiber
consumption in the European diet is partially due
to the refining of cereals. Most claims concerning
fiber content refer to the inherent fibers from
wholegrain flour. Fibers enrichment of several
bakery products has recently been tested using an
ingredient containing 95 per cent short chain
fructo-oligosaccharides. These soluble fibers are
naturally found in many vegetables including
wheat, rye, onion, Jerusalem artichoke, and are
structurally close to sucrose, therefore behaving
like sugar regarding theology.
. Sorbic acid
is effective to control mold growth in bakery
products at level of 0.125% to 0.3 per cent.
The economic losses associated with bakery
products, another concern is the possibility of
mycotoxins production. Eurotium species are
usually the first fungi to colonize improperly
dried, stored commodities, and when they grow,
they increase the level of available water allowing
other species (e.g. Aspergillus and Penicillium) to
thrive. Eurotium sp. do not produce any
significant mycotoxins [4]. Hunt and Robbins
IJPBA, Jan - Feb, 2012, Vol. 3, Issue, 1
, told that bakery products accounted for
approximately 9 per cent of total food
expenditure, with bread king the most important,
accounting for 27 per cents of each dollar spent.
However, the consumption of white bread has
decreased in the last two decades in western
societies while sales of whole wheat bran bread
have increased due to health concerns. Sales of
flat breads, especially pita bread, have been
P.Saranraj et al. / Microbial Spoilage of Bakery Products and Its Control by Preservatives
© 2010, IJPBA. All Rights Reserved.
increasing in western societies due to migration of
cultures and societies. Several methods can be
used to classified bread products including
methods of fermentation, bread volume, and water
In the last few years, the bakery products and flour
confectionary sector has witnessed particularly
intense technological progress which has brought
clear and tangible changes, not only in terms of
commercial and qualitatively characteristics of the
products, but also in terms of process innovation.
Usually bakery products are packaged in plastic
films after baking and cooling and they consumed
within 1or 2 months post process contamination is
unavoidable. Bakery products are classified as
products of intermediate moisture content on the
other hand the nutritional composition of different
bakery products will differ and influence fungal
growth. Contamination by xerophilic organisms in
these kind of products usually comes from the
post baking cooling period, as the cooking
temperature is normally enough to eliminate
previous contamination [6].
Bakery products are an important part of food
expenditure. Consumption of bakery products
have been falling since the end of world war two
in some industrialized countries such as the USA,
Canada, the UK and Australia. According to Hunt
and Robbins (2009)[7] bakery products accounted
for 9 per cent of the average weekly food
consumption. Anon (2000)[8] estimated the
consumption of bread in the UK was still 41.5 kg
per person in 1990. Baur (2001)[9] estimated the
western European bread market to be 23.000
million French francs. For several thousands of
years, man has used wheat and other cereals to
produce bread with an average consumption of
about 65 kg of bread per capita per year in
Europe, it remains and important constituent of a
balanced healthy diet [10]
Microbiological spoilage is often the major factors
limiting the shelf life of bakery products. Spoilage
from microbial growth causes economic loss for
both manufacturers and consumer. These losses
could be due to many individual cases such as,
packaging, sanitary practice in manufacturing,
storage conditions and product turnover. Rachel
Needham et al. (2004)
convenience, taste and
freshness determine to a great extent the appeal of
bread products and are expected to remain the
driving factors for purchases of bakery products.
[11] tested the microbial
spoilage caused by bacteria, yeast and fungi and
enzymic spoilage caused by lipoxygenase can be
differentiated from one another and from
unspoiled bread analogues after 48 hours using
Cluster analysis, prior to signs of visible spoilage.
Analysis of the bread analogues with gas
chromatography mass spectrometry identified
volatiles produced by the different spoilage types
and unspoiled bread analogues. Microbial analysis
showed that the levels of each microorganism
used increased with time.
Francesca Valerio et al. (2009)[12] characterized
125 presumptive LAB isolates by repetitive extra
genic palindromic PCR (REP-PCR) and
sequence analysis of the 16s rRNA gene, leading
to the identification of the following species:
Weissella confusa, Weissella cibaria, Leuconostoc
citreum, Leuconostoc mesenteroides, Lactococcus
lactis, Lactobacillus rossiae and Lactobacillus
plantarum. The REP-PCR results delineated 17
different patterns whose cluster analysis clearly
differentiated Weissella cibaria from Weissella
confusa isolates.
3.1. Bacterial spoilage
Bacteria also have a potential to contaminate
baked products although their growth is more
restricted by low water activity and low pH. The
spores of Bacillus subtilis for examples are heat
resistant; 55 per cent remain active in amylase
after 20 minutes at 65°C. This microorganism,
which is present in raw ingredients, e.g., flour,
sugar, and yeast, causes rope in bread [13]. Ropey
bread is characterized by discoloration from
brown to black, the release of a rotten fruit odor
and having an extremely moist, stringy bread
crumb [14]. This problem usually occurs in the
summer season when the climate is warm and
humid [13]. Ropiness can develop very rapidly
under warm and humid conditions. So, it is a
common problem in the warm climates of
Mediterranean countries, Africa and Australia [15]
A major source of Bacillus contamination is from
the raw ingredients so ideally it would be
profitable for bakeries to use only ingredients with
low level of contamination. Ropey bread is caused
mainly by Bacillus subtilis but other species of
bacillus are capable of causing rope and these
include Bacillus licheniformis, Bacillus
megaterium and Bacillus cereus
IJPBA, Jan - Feb, 2012, Vol. 3, Issue, 1
. Ropy
spoilage in bread is first detected by an odour
similar to that of pineapple. Later, the crumb
becomes discoloured, soft and sticky to the touch,
which makes the bread inedible. The deterioration
of bread texture is due to slime being formed as a
result of the combined effect of the proteolytic
and amylolytic enzymes produced by some
Bacillus strains that results in slime formation.
P.Saranraj et al. / Microbial Spoilage of Bakery Products and Its Control by Preservatives
© 2010, IJPBA. All Rights Reserved.
This prevention of rope problems require strict
sanitary as well as good manufacturing practices
designed to control the spores of Bacillus species.
Preservatives, such as propionate, can be usually
used to eliminate this problem [16].
Staphylococcus aureus is one type of bacteria
known to contaminate pie fillings. This
microorganism has also been implicated in food
poisoning outbreaks from cream filled bakery
products [17]. He also noted that of the 323
outbreaks of food poisoning which occurred in
Britain between 1969 and 1972, cakes and
desserts contributed 3 per cent. Other bakery
ingredients, such as chocolate, desiccated coconut
and cocoa powder were found to be contaminated
with Salmonella [17]. For example, frozen pizza
was significantly affected by Salmonella
typhimurium [18]
Yeast problems occur in bakery products. Wild
yeast include Trichosporon variable,
Saccharomyces, Pichia and Zygosaccharomyces.
Saccharomyces sp. produce white spots in bread
can be leading to the term chalk bread. Legan and
Voysey (1981)
3.2. Yeast spoilage
Mould spoilage is a serious and costly problem for
bakeries and use of preservatives is therefore an
attractive means to diminishes the spoilage and
insure the food safety. However, consumers today
are not in favor of additives as preservatives and
an urge to reduce the quantities used exists within
the bakery industry
studied that the yeast problems
in bakery products can be divided into two types:
(a) visible yeast which grows on the surface of the
bread in white or pinkish patches and, (b)
fermentative spoilage associated with alcoholic
and essence odors and hence osmophilic yeasts.
Yeasts, which cause surface spoilage of bread, are
mainly Pichia burtonii ("Chalk mold").
Contamination of products by osmophilic yeasts
normally results from unclean utensils and
equipment. Therefore, maintaining good
manufacturing practices will minimize the
contamination by osmophilic yeasts.
3.3. Mold spoilage
[20]. Mold growth is by far the
major factor limiting shelf life of high and
intermediate bakery products. In general, most
molds prefer high aw values (>0.8) while a few
xerophilic molds prefer to grow at aw values as
low as 0.65. Mold growth on bakery products is a
serious problem that results in economic losses.
Furthermore, losses of products due to mold
spoilage are between 1 and 5 per cent depending
on the type of product, season, and the method of
processing [21]. According to Hickey (1998)[22],
losses due to mold spoilage in the bakery industry
average about 200 million pounds of product each
Mold spores are generally killed by the baking
process in fresh bread and other baked products
[23]. Therefore, for bread to become moldy, it must
be contaminated either from the air, bakery
surfaces, equipment, food handlers or raw
ingredients after baking during the cooling, slicing
or wrapping operations. This means that all
spoilage problems caused by molds must occur
after baking. The mold spore counts are higher in
the summer months than in the winter due to
airborne contamination in the warmer weather and
more humid storage conditions. Furthermore,
moisture condensation on a product's surface, due
to packaging prior to being completely cooled,
may be conductive to mold growth. Jarvis
(2001)[24] found that mold spoilage caused
undesirable odors and is often found on the
surface of the product. The most common molds
found in bakery products are: Rhizopus sp.,
Aspergillus sp., Penicillium sp., Monilia sp., Mucor
sp. and Eurotium sp.
4.1 Effect of temperature, pH and water
Physical factors are the important factor
governing mold free shelf life of bakery products.
It plays a decisive role when molds compete with
bacteria to spoil high moisture foods [25]. Molds
tend to be less fastidious in their relationships to
pH than bacteria. Generally, molds are tolerant of
acid conditions and favour an acidic pH (3.5-5.5).
Therefore, foods with pH value <4.5 are not
usually spoiled by bacteria but are more
susceptible to mold spoilage.
Abellana et al. (1999)[26] to obtained a method for
studying the growth of xerophilic fungi on bakery
products, and to determine the effect of water
activity (aw), temperature, isolates and their
interaction on mycelial growth of Eurotium sp.
The results showed that there were intra-isolate
differences (P, 0.001) due to water activity (aw),
temperature, isolate, and two-and three way
interaction. Optimum growth of all isolates over
water activity (aw) temperature range tested
showed optimum at 0.90 aw and 30 °C, with an
interval of growth rate of 3.8-5.1mm d-1 at 0.75
aw, growth was less than 0.15 mm. d-1.
Temperature plays a dominant role in mold
growth and in the germination of spores. The
majority of molds grow within a temperature
range of 18.3-29.4 °C
IJPBA, Jan - Feb, 2012, Vol. 3, Issue, 1
when the temperature of
P.Saranraj et al. / Microbial Spoilage of Bakery Products and Its Control by Preservatives
© 2010, IJPBA. All Rights Reserved.
bakery product is reduced from that for optimum
temperature. Chamberlain (1993)[28]
Abellana et al. (2001)
reported that
the reduction in the storage temperature from 27
°C to 21 °C doubled the mold free shelf life of
cake and emphasized the need for care during
distribution and storage.
[29] compared the effect of
temperature and water activity and their
interactions on the rate of mycelia growth of
Penicillium aurantiogriseum, Penicillium
chrysogenum, Penicillium corylophilum and
Aspergillus flavus on a sponge cake analogue. As
expected, growth rates showed dependence on aw
and temperature. However, no significant
differences were observed in the growth rates of
different isolates. The minimum aw values for
growth of the Penicillium sp. was 0.85 – 0.90.
Aspergillus flavus was able to grow at 0.90 aw
when the temperature was above 15.8 °C. They
showed that fungal growth by these species on a
sponge cake analogue, with a composition similar
to usual bakery products, was prevented if the aw
is kept at 0.85.
Vytrasova et al. (2002)[30] detected, isolated and
identified xerophilic fungi Eurotium amstelodami,
Eurotium chevalieri, Eurotium herbariorum,
Eurotium rubrum and Wallemia sebi. The
resistance of these fungi against elevated
temperature and preserving agents was
investigated. It was found that Eurotium sp. were
more resistant than Wallemia sebi. Preservation
against xerophilic fungi was more effective with
the use of sorbic acid than with calcium
Guynot et al. (2003)[31] used a sponge cake
analogue was used to study pH, water activity
(aw), and carbon dioxide (CO2) levels on the
growth of seven fungal species commonly causing
bakery product spoilage (Eurotium amstelodami,
Eurotium herbariorum, Eurotium repens,
Eurotium rubrum, Aspergillus niger, Aspergillus
flavus and Penicillium corylophilum). Water
activity, CO2 and their interaction were the main
factors significantly affecting fungal growth.
Water activity at levels of 0.80 to 0.90 had a
significant influence on fungal growth and
determined the concentration of CO2 needed to
prevent cake analogue spoilage. At an aw level of
0.85, lag phases increased two fold when the level
of CO2 in the headspace increased from 0 to 70
per cent. In general, no fungal growth was
observed for upto 28 days of incubation at 25°C
when samples were packaged with 100 per cent
CO2, regardless of the aw level.
Elena Guynot et al. (2005)[32] studied the mould
growth on fermented bakery product analogues
(FBPA) of two different pH (4.5 and 5.5),
different water activity (aw) levels (0.80 0.90)
and potassium sorbate concentrations (00.3%) by
using seven moulds commonly causing spoilage
of bakery products (Eurotium sp., Aspergillus sp.
and Penicillium corylophilum). For the description
of fungal growth as a function of aw, potassium
sorbate concentration and pH, 10 terms
polynomial models were developed. Modelling
enables prediction of spoilage during storage as a
function of the factors affecting fungal growth. At
pH 4.5 the concentration of potassium sorbate
could be reduced to some extent only at low levels
of aw, whereas at pH 5.5 fungal growths were
observed even by adding 0.3 per cent of potassium
Mariona Arroyo et al. (2008)[33]
Samapundo et al. (2010)
examined nutrient
assimilation by two mycotoxigenic spoilage fungi
(Penicillium verrucosum, Aspergillus ochraceus)
and four other food spoilage fungi (Penicillium
coryolophilum, Penicillium roqueforti,
Cladosporium herbarumi, Eurotium repens), of C-
sources in wheat bread in relation to a biotic
factors of water availability, pH and temperature
and the presence/absence of a preservative,
potassium sorbate. These studies were to
understand the relative potential co-existence,
nutritional partitioning and niche exclusion in
bread-based matrices. The niche size decreased
significantly with decrease in water availability,
temperature and pH. There were also significant
interactive effects between pH and the
preservative. The data were used to determine the
niche overlap indices (NOI) of competing fungi
relative to the two ochratoxigenic species. These
showed that Penicillium verrucosum and
Aspergillus ochraceus were nutritionally
dominant over the other species.
4.2. Effect of salt tolerance:
[34] evaluated the effect of
NaCl and various NaCl replacers (CaCl2, MgCl2,
KCl and MgSO4) on the growth of Penicillium
roqueforti and Aspergillus niger at 22°C. In
addition, challenge tests were performed on white
bread to determine the consequences of NaCl
reduction with or without partial replacement on
the growth of Penicillium roqueforti. The results
obtained concluded that at equivalent water phase
concentrations the isolates exhibited differing
sensitivities to the salts evaluated with NaCl and
MgCl2 having the greatest inhibitory action on the
growth of Aspergillus niger and Penicillium
roqueforti, respectively. MgSO4
IJPBA, Jan - Feb, 2012, Vol. 3, Issue, 1
had the least
P.Saranraj et al. / Microbial Spoilage of Bakery Products and Its Control by Preservatives
© 2010, IJPBA. All Rights Reserved.
antifungal activity. At equivalent molalities,
CaCl2 had in general the largest antifungal
activity. Although the water activity (aw) lowering
effects of the compounds studied play a large role
in explaining the trends observed, at equivalent
water phase concentrations MgCl2 was found to
have a smaller inhibitory effect on Aspergillus
niger than that expected from its aw
Several methods can be used to control mold
growth on bakery products including
reformulation, freezing, and most commonly, the
use of preservatives.
5.1. Reformulation to reduce product a
effect. The challenge tests revealed that no
difference occurred in the growth of Penicillium
roqueforti on standard white bread, bread with 30
per cent less NaCl and bread in which 30 per cent
of the NaCl has been partially replaced by a
mixture of KCl and Sub-salt.
Reformulation involves a reduction of available
water e.g., aw in bakery products to obtain a longer
shelf life. Reduction in product aw can be achieved
by dehydration, either through evaporation or
freeze-drying or by high osmotically active additives
e.g., sugars and salts, incorporated directly into the
food. The degree of aw reduction is of practical
significance in making a food non-perishable. The
response to a given degree of aw varies greatly
among microorganisms in different environments
Water contained in solutions of sugars and salt
becomes unavailable to microbes due to the
increased concentration of crystalloid.
Furthermore, microbes are directly damaged
osmotically by concentrations of these substances.
This effect may be due to the adverse influence of
lowered water availability on all metabolic
activities, since all chemical reaction of cells
require an aqueous environment. Control of mold
growth in bakery products normally relies on
maintaining a sufficiently low aw. For example, an
aw of 0.75 can give a 6 month extension in mold
free shelf life. Higher aw levels e.g., above 0.77
will only result in a short extension of shelf life.
However, since low aw can adversely affect the
quality of the product and cause changes in shape
and texture, care must be taken when reducing
product aw [36]
Freezing has been used for long term preservation
of bakery products particularly, cream filled
products. Quick freezing is important in
controlling the formation of ice crystals. Large ice
crystals are formed when the rate of freezing is
slower; the large crystals can disrupt membranes
and internal cellular structures
5.2. Freezing
[37]. Cakes, cookies,
short cake, and pancakes are commonly frozen
and marketed in the frozen form. Bread has been
held fresh for many months by storage at -22°C
[38]. In contrast to fresh bread, which stales in less
than a week, frozen bread stales very slowly.
Therefore, the lower the temperature, the more
slowly it stales. Desrosier (2006)[38] reported that
bread frozen quickly after baking and held for one
year at -18°C, was equivalent in softness to fresh
bread held for two days at 20°C.
5.3. Preservatives
Preservatives are most commonly used to control
mold growth in baked goods. The Code of Federal
Regulations (CFR) defines preservatives “as an
antimicrobial agent used to preserve food by
preventing growth of microorganisms and
subsequent spoilage”. There are two
classifications of preservatives: chemical and
natural permitted chemical mold inhibitors in
bread include acetic, sorbic, propionic acids and
their salts. Natural food preservatives, such as
cultured products, raisins, vinegar, are identified
by their common name on the ingredient
Marin et al. (2002)[39] used the hurdle technology
approach to prevent fungal growth of common
contaminants of bakery products including
isolates belonging to the genera Eurotium,
Aspergillus and Penicillium. Several levels
(0.003%, 0.03% and 0.3%) of calcium propionate,
potassium sorbate and sodium benzoate were
assayed on a model agar system in a full-factorial
experimental design in which the other factors
assayed were pH (4.5, 6 and 7.5) and aw (0.80,
085, 0.90 and 0.95). Potassium sorbate was found
to be the more suitable preservative to be used in
combination with the common levels of pH and
Guynot et al. (2004)
w. [40] applied a hurdle
technology approach to control common mold
species causing spoilage of intermediate moisture
bakery products (Eurotium sp., Aspergillus sp.,
and Penicillium corylophilum), growing on a
fermented bakery product analogue (FBPA). The
factors studied included a combination of different
levels of weak acid preservatives (potassium
sorbate, calcium propionate, and sodium benzoate;
0–0.3%), pH (4.5–5.5) and water activity (aw
IJPBA, Jan - Feb, 2012, Vol. 3, Issue, 1
0.80–0.90). Potassium sorbate was found to be the
most effective in preventing fungal spoilage of
P.Saranraj et al. / Microbial Spoilage of Bakery Products and Its Control by Preservatives
© 2010, IJPBA. All Rights Reserved.
this kind of products at the maximum
concentration tested (0.3%) regardless of aw. The
same concentration of calcium propionate and
sodium benzoate was effective only at low aw
levels. On the other hand, potassium sorbate
activity was slightly reduced at pH 5.5, the 0.3 per
cent being only effective at 0.80 aw
Francesca Valerio et al. (2009) .
[41] characterized
seventeen strains by a different REP-PCR pattern,
were screened for their antifungal properties. They
were grown in a flour-based medium, comparable
to a real food system, and the resulting
fermentation products (FPs) were tested against
fungal species generally contaminating bakery
products, Aspergillus niger, Penicillium roqueforti
and Endomyces fibuliger. The results of the study
indicated a strong inhibitory activity comparable
to that obtained with the common preservative
calcium propionate (0.3%w/v) often Lactic acid
bacterial strains against the most widespread
contaminant of bakery products, Penicillium
roqueforti. The screening also highlighted the
unexplored antifungal activity of Lactobacillus
citreum, Lactobacillus rossiae and Weissella
cibaria, which inhibited all fungal strains to the
same or a higher extent compared with calcium
6.1. Sorbic acid and sorbates
Sorbic acid (CH3-CH=CH-CH=CH-COOH) and
its potassium salt, are recognized as effective
antimold agents, and have been considered
historically safe for food use. Sorbic acid and
potassium sorbate are Generally Regarded As
Safe(GRAS) for their use in foods. This acid or
its potassium salts, has been used to retard
microbial degradation in a large variety of food
items. Major groups of foods in which sorbate has
been used commercially because of its
antimicrobial activity include baked goods, cheese,
cake, chocolate coatings, fish products, fruit, butter,
salad, vegetables and wine. The usefulness of
sorbic acid as a mold inhibitor in bakery products
such as cakes, cake mixes, pies, pie filling,
doughnuts, etc. has also been demonstrated by
Gorton (1999)[42]. In general, sorbic acid is
effective against bacteria, and especially molds and
yeasts. The major commercial use of sorbate is as a
fungistatic. Several studies have demonstrated the
inhibitory effect of potassium sorbate on mold
growth in food products. Ray and Bullerman
(2001)43 reported that potassium sorbate exhibited
a great effect on the growth of Aspergillus niger
and Penicillium species. Sauer and Burroughs
(1993)[44] observed that mold was inhibited for 2
weeks by using 0.5 per cent potassium sorbate.
The levels of sorbate used in bakery products ranges
from 0.001-0.3 per cent [45]. These concentrations
have no major impact on food quality, but higher
levels may cause undesirable changes in taste and
flavor. Sorbates are more than twice as effective as
propionates in inhibiting mold growth in bakery
products, but have an adverse effect on yeast,
reducing loaf volume and making dough sticky and
difficult to process. This problem can be overcome
by either spraying sorbate onto the product's surface
after baking or mixing anhydrates of sorbic acid
with fatty acids, such as palmitic. In addition,
sorboyl palmitate has also been successful in
controlling mold growth without interfering in the
fermentation process. The heat of the baking process
hydrolyses sorboyl palmitate and releases sorbic
acid which inhibits molds during storage [45]. Sorbate
acts synergistically with sodium chloride, calcium
propionate, sodium propionate, citric acid and
sucrose achieving a longer shelf life.
6.2. Propionic acids and its salts
Propionic acid, an aminocarbolic acid (CH3CH2-
COOH), is a naturally occurring organic acid and
is an oily liquid with a slightly pungent,
disagreeable rancid odor. Its salts are white, free-
flowing powders with a slight cheese like flavor
[46]. Propionates were selected on the basis that
higher MW fatty acids had a higher antimicrobial
effect. This acid or its salt can be used to prevent
the bacterial spoilage of bread known as rope
caused by certain Bacillus sp. Several studies have
also reported the effects of propionic acid and its
salt on mold growth. Concentrations of propionate
ranging from 8 to 12 per cent have been reported
effective in controlling mold growth on the
surface of bakery products [46]. However, not all
molds were equally sensitive to the inhibitory
effect of propionate. For example, at 0.3 per cent
calcium propionate, growth of Monilia sitophila
and Pencillium virdiicatum in bread was inhibited
for 2 days and 0.5 day respectively.
Marin et al. (2002)[47]
IJPBA, Jan - Feb, 2012, Vol. 3, Issue, 1
tested the use of weak-acid
preservatives (potassium sorbate, calcium
propionate, and sodium benzoate) to prevent
spoilage by Aspergillus niger, Aspergillus flavus,
and Penicillium corylophilum in analogs of a
bakery product. A hurdle technology approach has
been considered in which factors other than
preservatives are pH and water activity. Potassium
sorbate has been found to be the most effective in
preventing fungal spoilage of this kind of products
at the maximum concentration tested (0.3%).
Suboptimal doses (0.03%) of all preservatives
tested led to an enhancement of growth of
Aspergillus and Penicillium isolates.
P.Saranraj et al. / Microbial Spoilage of Bakery Products and Its Control by Preservatives
© 2010, IJPBA. All Rights Reserved.
Marin et al. (2003)[48]
Suhr and Nielsen (2004)
studied the effects of sorbic
acid and potassium sorbate on growth of different
Eurotium isolates when added to a bakery product
analogue were tested under different
environmental conditions. Water activity of the
products was adjusted to values in the range of
0.75-0.90, and storage temperatures were in the
range of 15-30 °C. Preservatives were added in
concentrations ranging from 0.025 per cent to 0.2
per cent. It was observed that 0.025 per cent and
0.05 per cent concentrations always enhanced the
isolates growth, while 0.1 per cent had little
preservative effect. Finally, even the highest
concentration (0.2%) was not suitable as it only
controlled fungal growth under certain water
activity and temperature levels.
[49] investigated the
inhibition of spoilage organisms from bakery
products by weak acid preservatives in
concentrations of 0%, 0.003%, 0.03% and 0.3%
(w/v) experimentally on a substrate media with
water activity (aw) and pH ranging from sourdough
fermented acidic rye bread to alkaline intermediate
moisture sponge cake types (aw 0.80-0.95, pH 4.7-
7.4). Initially, rye bread conditions (aw 0.94-0.97
and pH 4.4-4.8) in combination with calcium
propionate. Results showed that the highest
concentration of propionate (0.3%) at all conditions
apart from high aw (0.97) and high pH (4.8) totally
inhibited fungal growth for a 2 week period, with
the exception of Penicillium roqueforti, Penicillium
commune and Eurotium rubrum.
In recent years, bio-preservative (The use of
microorganisms and their metabolites to prevent
spoilage and to extend the shelf life of foods) has
gained increasing interest due to consumer’s
demands. Lactic acid bacteria (LAB) as bio-
preservation organisms are of particular interest.
They have been used for centuries as starter
cultures in the food industry and are able to
produce different kind of bioactive molecules,
such as organic acids, fatty acids, hydrogen
peroxide and bacteriocins. The antifungal activity
of LAB is documented [50]
Ozay Mentes et al. (2005)
. [51] studied the effect of
two different sourdoughs, produced with
Lactobacillus plantarum and Lactobacillus
alimentarius, with antimicrobial activities on
inhibition of rope-forming Bacillus strains in wheat
bread was studied. Addition of 15 per cent or 20
per cent low pH (pH 3.5–4.0) sourdough to bread
dough, which were produced by using two strains
(Lactobacillus plantarum and Lactobacillus
alimentarius ) separately, prevented the generation
of visual rope caused by Bacillus subtilis and
Bacillus licheniformis. However, adding 10 per cent
sourdough was not enough to prevent the generation
of visual rope. When repeated with sourdoughs with
a higher pH (pH > 4), additives at 10 per cent or 15
per cent did not prevent the generation of rope,
whereas additives at 20 per cent prevented the
generation of visual rope caused by both Bacillus
subtilis and Bacillus licheniformis.
Sana M’hir et al. (2007)[52] collected thirty
samples of fermented wheat dough microflora
from different Tunisian bakeries. Forty per cent of
the samples contained approximately 106cfu/g of
mesophilic aerobic bacteria (MAB). Lactic acid
bacteria (LAB) and yeasts dominated the
microflora of these samples. They varied from 105
to 108cfu/g. The LAB/yeasts ratio arising from
microbial counts were varied between 1/1 and
200/1. More than 50 per cent of the analysed
samples were deprived of Enterococcus sp. The
content of contaminating microflora like coliforms
and mesophilic Bacillus ranged from 102 to
104cfu/g. The ratio between LAB and coliforms
were estimated to about 26 per cent of the
analysed samples. This ratio is more important
between LAB and mesophilic Bacillus. The
LAB/mesophilic Bacillus ratio was about 104 for
45 per cent of the analysed samples. However,
Micrococcaceae were absent in all samples.
Ryan et al. (2008)[53]
Carla Luciana Gerez et al. (2009)
investigated that sourdough
fermented by antifungal Lactobacillus plantarum
strains was investigated for the ability to inhibit
growth of common bread spoilage fungi. In both
in vitro and sourdough wheat bread system, the
antifungal sourdoughs significantly affected the
outgrowth of Aspergillus niger, Fusarium
culmorum or Penicillium expansum spores.
However on wheat bread outgrowth of
Penicillium roqueforti spores was not affected. In
an attempt to reduce the amounts of chemical
additives in bread, the antifungal sourdoughs were
used in combination with calcium propionate
(CAP) and possible synergistic effects were
evaluated. Presence of 3000 ppm CAP in the
bread did not affect the outgrowth of Penicillium
roqueforti, whereas outgrowth of the other fungi
was retarded. A strong synergistic effect was
observed when CAP and antifungal sourdoughs
were combined into the bread formulation, and
outgrowth of Penicillium roqueforti was affected.
IJPBA, Jan - Feb, 2012, Vol. 3, Issue, 1
evaluated the
ability of lactic acid bacteria to inhibit
Aspergillus, Fusarium and Penicillium, the main
contaminants in bread. Only four strains
(Lactobacillus plantarum, Lactobacillus reuteri
P.Saranraj et al. / Microbial Spoilage of Bakery Products and Its Control by Preservatives
© 2010, IJPBA. All Rights Reserved.
and Lactobacillus brevis from 95 strains tested
displayed antifungal activity. The major
antifungal compounds were acetic and
phenyllactic acids. The fermentation quotient (FQ
= 2.0) and the leaven volume (80 cm) of dough’s
with Lactobacillus brevis and yeasts were higher
than dough’s without Lactobacillus brevis. The
inclusion of antifungal LAB strains in the starter
culture allowed a reduction in the concentration of
the chemical preservative calcium propionate by
50 per cent.
The present review concludes the predominant
efficacy of preservatives in bakery foods. Mold
spoilage is still a major problem limiting the shelf
life of many high and intemediate moisture bakery
products. Losses due to mold spoilage have been
resulting in lost revenue to the baking industries.
Therefore, methods to control mold growth and to
extend the shelf life of bakery products is of great
economic importance to the baking industry
where an increased demand in global consumption
exists. Other measures as good hygiene in the
bakeries and if necessary complementary post
packaging heat treatments or modified atmosphere
packaging is the best alternatives.
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IJPBA, Jan - Feb, 2012, Vol. 3, Issue, 1
... In most countries and cultures, bakery products are the important staple foods [6]. They are a good source of several necessary nutrients such as carbohydrates, proteins, fats, vitamins, and minerals, and are the most widely consumed food on the planet [6]. ...
... In most countries and cultures, bakery products are the important staple foods [6]. They are a good source of several necessary nutrients such as carbohydrates, proteins, fats, vitamins, and minerals, and are the most widely consumed food on the planet [6]. However, harmful microbes can enter bakery foods through inappropriate handling and storage, causing sickness in consumers [7]. ...
... Because freshly baked products have a low water activity and are baked at a high temperature, they are devoid of germs and do not contain pathogenic microorganisms, making them a safe food from a microbiological standpoint [6,8]. However, different physical, chemical, and microbiological factors, such as slicing machinery, post-baking contamination from the handler, bread coolers, conveyor belts, racks, and high moisture, can all affect bakery product deterioration [6]. ...
Full-text available
Bread is a significant staple food that can be consumed without further processing. However, given that eating contaminated bread could have a negative impact on consumers' health, its safety has become a top concern for the food industry. The aim of the study was to assess the knowledge, attitudes, and practices of bread makers on food safety and hygiene. This was a cross-sectional descriptive study involving 416 bread bakers from the registered local and contemporary bread bakeries in GBA and Brikama. Data was collected using a structured and semi-structured questionnaire which was interviewer-administered and observation checklist. Thirty bread samples each from the bakeries and the retailer shops were analyzed for pathogenic contamination. Data were analyzed using a descriptive statistic, chi-square, and t-test at P=0.05. The majority of the respondents were males 96.4% and in the age range of 25-54 years. Several (88.7%) had good knowledge of food safety and hygiene. The overall attitude scores revealed that about 94% of the respondents had a poor attitude towards food safety and 86.6% of the respondents in two bakeries had fair practice towards food hygiene and safety (70% and 16.8%) respectively. There was a significant relationship between the knowledge (p=0.001), attitude (p=0.002), and practices (p=0.001) of the respondents in local and contemporary bakeries. Bread analysis showed that only a third of the bread sampled from the two bakeries (50% and 40%) were contaminated, while almost all the bread sampled from the bread sellers (40% and 20%) were contaminated. The bread is more likely to be contaminated by pathogenic and non-pathogenic microorganisms due to poor bakery hygiene conditions, bakers' handling of bakery procedures, and vendors' attitudes. Therefore, all bakery employees and bread vendors should be trained on proper handling of bread to prevent outbreaks of food borne illnesses.
... Microbiological spoilage is a major problem for bakery products, often limiting their shelf life. Microbial growth causes economic loss for both manufacturers and consumers as a result of poor packaging, sanitation practices in manufacturing, storage conditions and low product turnover [28]. Microorganism can be found in raw materials of the bak- ...
... Microbiological spoilage is a major problem for bakery products, often limiting their shelf life. Microbial growth causes economic loss for both manufacturers and consumers as a result of poor packaging, sanitation practices in manufacturing, storage conditions and low product turnover [28]. Microorganism can be found in raw materials of the baking goods which contaminated during processing and packaging, or immediately after the oven. ...
... Saccharomyces sp. produces white spots in bread, leading to the term chalk bread [28]. ...
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Polymeric materials including plastic and paper are commonly used as packaging for bakery products. The incorporation of active substances produces functional polymers that can effectively retain the quality and safety of packaged products. Polymeric materials can be used to produce a variety of package forms such as film, tray, pouch, rigid container and multilayer film. This review summarizes recent findings and developments of functional polymeric packaging for bakery products. Functional polymerics are mainly produced by the incorporation of non-volatile and volatile active substances that effectively retain the quality of packaged bakery products. Antimicrobial agents (either synthetic or natural substances) have been intensively investigated, whereas advances in coating technology with functional materials either as edible coatings or non-edible coatings have also preserved the quality of packaged bakery products. Recent patents demonstrate novel structural packaging designs combined with active functions to extend the shelf life of bakery products. Other forms of active packaging technology for bakery products include oxygen absorbers and ethanol emitters. The latest research progress of functional polymeric packaging for bakery products, which provides important reference value for reducing the waste and improving the quality of packaged products, is demonstrated. Moreover, the review systematically analyzed the spoilage factors of baked products from physicochemical, chemical and microbiological perspectives. Functional packaging using polymeric materials can be used to preserve the quality of packaged bakery products.
... Due to physical, chemical, and microbiological causes, bakery products can degrade. Mold growth and its complications cause a signifcant microbiological loss in bakery products [2]. Te primary bakery goods are bread and cake. ...
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The application of vacuum packaging (VP) and nonvacuum packaging (NP) of injera, with or without preservative added (sodium benzoate), has been studied for 15 days with the aim of determining their effect on the shelf-life and staling of injera. Samples were tested for microbial load analysis, moisture content (MC), pH, and color “L” value (lightness) determination, visible mold sign inspection, and sensory quality evaluation. Oxygen exclusion of the packaging methods and antimicrobial activities of preservative used, prolong the storage duration of injera without visible mold growth to more than 15 days; with VP (vacuum packaging), VP+ (vacuum packaging with preservative), and NP+ (nonvacuum packaging with preservative) treatments. Among these, VP+ had the least microbial load (5.3∗101 & 9.0∗101 bacterial & yeast and mold colony forming unit (cfu)/g, respectively). But it was least effective regarding staling as it had the least average scoring of MC, pH, and L value (60.96%, 3.33, and 45.92, respectively) and sensory acceptability, basically due to the crumbling effect of the packaging method used. Besides, NP + had a lower microbial load (7.5∗101 bacterial cfu/g and 9.0∗101 yeast and mold cfu/g). Despite VP and VP+, NP+ was a relatively effective method regarding sensory acceptability and staling as it had 62.73%, 3.32, and 48.70 average MC, pH, and L value, respectively. Generally, packaging methods and preservative used were found to have a significant effect (P<0.05) on microbial load, physico-chemical properties, and sensory attributes of injera. Moreover, it was proved that NP+ was the most effective method to improve the shelf life and staling of injera.
... Food spoilage by fungi is a major concern for the food industry (Saranraj & Geetha, 2012). In bakeries, fungal conidia from raw materials are broadly eliminated during baking (Garcia, Pia, Freire, Copetti, & Sant'Ana, 2019a), however fresh baked bread and other bakery products re-contaminate mainly during cooling and slicing processes, when airborne spores are deposited onto ready-to-eat products (Viljoen & Von Holy, 1997;Garcia, Bernardi, & Copetti, 2019b). ...
Controlling food spoilage fungi remains a challenge for food industries, and regulations on the usage of chemical disinfectants are becoming restrictive. Then, this study aimed to evaluate electrolyzed water (EW) as a sustainable alternative for food spoilage fungi inactivation. The experiment was carried out according to the protocol for testing the antifungal effects of chemical sanitizers by the European Committee for Standardization (CEN), using acidic electrolyzed water (AEW-AAC: 85 ppm; pH: 2.65; ORP: 1120 mV) and a basic electrolyzed water (BEW- pH: 11.12; ORP: -209 mV) to inactivate spoilage fungi strains from bread (Hyphopichia burtonii and Penicillium roqueforti) and cheese (P. roqueforti and Penicillium commune), besides the standard fungi for this type of essay (Candida albicans and Aspergillus brasiliensis). AEW presented a higher antifungal effect, inactivating an average of 89% of the exposed population when compared to its respective BEW, which inactivates about 81.5%. In general, the standard strains A. brasiliensis (ATCC 16404) and Candida albicans (ATCC 24433) were more sensitive to both AEW and BEW than the food-spoilage strains. Among those, P. roqueforti strains were the most sensitive, followed by P. commune strains, while H. burtonii strains were the most tolerant. EW can be a sustainable alternative for product surface and facility cleaning with further antifungal action when a sanitization step is not mandatory or needed. Future studies searching for conditions to improve the antifungal action of EW could make their industrial usage more viable.
... For the following parameters, the best and most economic quantity of the PS that can be used as a preservative was also determined. A higher concentration of preservatives increases the shelflife, but the higher concentration does not only lead to high production cost but can lead to serious health hazards [39]. Figure 3 shows the result obtained from the evaluation shelflife using PS with time on the pH of GS. ...
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Sweet potato is one of the largest sources of starch. Due to this fact, it can be utilized to obtain value-added products. This research aims at optimizing the operation parameters for sweet potato-based glucose syrup production and preservation. A maximum yield of starch isolated using distilled water was found to be 31.59%. The produced starch was then subjected to acidic hydrolysis to obtain glucose syrup with a dilute sulfuric acid concentration of (0.5, 1, and 1.5%) at temperatures (130, 140, and 150 °C) and time (25, 30, and 35 min). The total reducing sugar content of the hydrolysates was determined using the dinitro salicylic acid method and an optimum reducing sugar amounting to 242.3 g/L was found at 1.34% sulfuric acid concentration, 140.89 °C temperature, and 32.96 min. The moisture, dry matter, ash, density, viscosity, and pH of the product were found to be 26%, 74%, 0.26%, 1.37 g/mL, 5.63, and 4.9, respectively. Since glucose syrup has a short shelf-life during storage, potassium sorbate having concentrations of 0, 0.025, 0.05, 0.075, and 0.1% were studied for 60 days to sustain the shelf-life of glucose syrup. Potassium sorbate concentration 0.05% which is within the permitted level was identified as a suitable preservative to retain the quality and extend the shelf-life of glucose syrup at room temperature.
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Antimicrobial peptides (AMPs) are a potential alternative to antimicrobial agents that have got considerable research interest owing to their significant role in the inhibition of bacterial pathogens. These AMPs can essentially inhibit the growth and multiplication of microbes through multiple mechanisms including disruption of cellular membranes, inhibition of cell wall biosynthesis, or affecting intracellular components and cell division. Moreover, AMPs are biocompatible and biodegradable therefore, they can be a good alternative to antimicrobial agents and chemical preservatives. A few of their features for example thermostability and high selectivity are quite appealing for their potential use in the food industry for food preservation to prevent the spoilage caused by microorganisms and foodborne pathogens. Despite these advantages, very few AMPs are being used at an industrial scale for food preservation as these peptides are quite vulnerable to external environmental factors which deter their practical applications and commercialization. The review aims to provide an outline of the mechanism of action of AMPs and their prospects as an alternative to chemical preservatives in the food industry. Further studies related to the structure–activity relationship of AMPs will help to expand the understanding of their mechanism of action and to determine specific conditions to increase their stability and applicability in food preservation.
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Bread staling and microbial growth is a complex physiochemical change that occurs during bread storage mainly reducing the quality and consumer acceptance. It is significant to understand the causes of physical, chemical, and microbial spoilage of bakery products in the food industry, to prevent quality decay and economic loss for manufacturers and consumers. Traditional packaging has limitations in protecting and preserving the final products’ safety, hygiene, and quality. Effective novel strategies must be included in food packaging, especially to minimize the organoleptic losses of baked foods during their shelf life. Furthermore, owing to the spread of foodborne diseases, which directly affect the safety of the products, customer demand is increasing significantly to reduce the use of synthetic preservatives instead of natural ones. Innovative packaging is altering the way food items are packed in several ways to extend and monitor product shelf life. Traditional packaging includes packaging food in synthetic polymer film; however, modern technology allows them to interact with active/functional substances. This paper discusses innovative bread packaging strategies such as modified atmosphere packaging (MAP), active packaging (AP), intelligent packaging (IP), biosensor, and nano packaging. Furthermore, MAP and AP have received greater attention in this study due to their considerable effect in prolonging the shelf life of bread and naturally preventing fungal activity, and have gained a lot of interest among producers and consumers in recent years.
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Bread products are a useful source of nutrients as a food source. Bread is made with flour as the main raw material which has hazards and risks to health depending on the duration and concentration of exposure and its microbial in it. Health complaints that are often experienced by baker workers are asthma, sensitization, conjunctivitis and skin problems. Literature study was carried out in this study using the PRISMA method on 9 relevant articles. In Ethiopia, bakery workers had higher health complaints compared to the control group. Milling mill workers had chronic symptoms such as 58.3%. In Italy, exposure to breadcrumb dust exceeds the threshold value and results in nasal inflammation and allergies. In Thailand there is evidence to support that flour dust can cause asthma. In France, flour dust may cause head and neck squamous cell cancer. In Egypt, exposure to flour dust increases the risk of workers' respiratory symptoms and disorders. The studies that have been carried out confirm that flour dust and its microbes can cause health problems for workers in the flour industry. Control of health impacts can be carried out by implementing controls starting from elimination/substitution, engineering, administration and use of personal protective equipment, especially those that protect respiratory function. Keywords: Workers, Flour, Asthma, Sensitization, Skin disorders, Hierarchy of control ABSTRAK Produk roti merupakan sumber nutrisi yang bermanfaat sebagai sumber makanan. Roti dibuat dengan bahan baku utama tepung yang memiliki bahaya dan risikonya terhadap kesehatan tergantung dari durasi dan konsentrasi pajanan serta mikroba di dalamnya. Keluhan kesehatan yang sering dialami pekerja pembuat roti adalah asma, sensitisasi, konjungtivitas dan masalah kulit. Literatur studi dilakukan dalam penelitian ini dengan metode PRISMA pada 9 artikel yang relevan. Di Ethiopia, pekerja roti memiliki keluhan kesehatan yang lebih tinggi dibandingkan dengan kelompok kontrol.Pekerja pabrik penggilingan tepung memiliki gejala kronis pernapasan sebesar 58,3%. Di Italia, pajanan debu tepung roti melebihi nilai ambang batas dan mengakibatkan peradangan hidung dan alergi. Di Thailand didapatkan ada bukti yang mendukung bahwa debu tepung dapat menyebabkan asma. Di Perancis, debu tepung berpotensi menyebabkan kanker sel skuamosa kepala dan leher. Di Mesir, pajanan debu tepung meningkatkan risiko gejala dan gangguan pernapasan pekerja. Penelitian-penelitian yang telah dilakukan mengkonfirmasi bahwa debu tepung serta mikrobanya dapat menyebabkan gangguan kesehatan pada pekerja di industri tepung. Pengendalian terhadap dampak kesehatan bisa dilakukan dengan menerapkan hierarki pengendalian dimulai dari eliminasi/subtitusi, rekayasa teknik, administrartif dan penggunaan alat pelindung diri khususnya yang melindungi fungsi pernapasan. Kata kunci: Pekerja, Tepung, Asma, Sensitisasi, Gangguan kulit, Hierarki pengendalian
Since ancient times, food additives have been used to increase the organoleptic properties and shelf life of food products. Till date, more than 2500 additives fall under intentional additive categories. Food additives are intentionally added to food items to serve some specific purposes (packaging, transport, storage, etc.). Generally, different laws have implemented on food additives by some regulatory bodies [Codex Alimentarius Commission, Food Safety and Standards Authority of India (FSSAI), Food and Agriculture Organization (FAO), etc.] regarding their limit for use in food products. For utilization of additives in food processing, it should be non-toxic, food grade, and non-reactive. This chapter presents a comprehensive summarization of food additives in terms of their classification, intake assessment, testing methods, advantages, maximum permissible limit, safety and risk associated with it.
The study of sensory, microbiological, and physical‐chemical properties are important in local products where the level of inspection and quality control are low. The present study aimed to determine the shelf‐life of an egg‐based moist cake, relating sensory, microbiological and physical‐chemical properties. Slices of Cavacas de Resende were collected, stored at 2 different temperatures (7 and 22 °C) and analysed over time (0, 6 hours, 1, 2, 4, 7 and 10 days). Salmonella, Bacillus cereus, Listeria monocytogenes and Escherichia coli, were not detected. On 10 days of storage at 22 °C results were above the allowed limit for Staphylococcus aureus. The counts of mesophiles, moulds and yeasts exceeded the allowed limits in the last days of storage at 22 °C. Most of sensory variables presented a positive and highly significant correlation with freshness, with emphasis to brightness (crust and batter), moist, softness and succulence. Hardness and fracturability (both instrumental) showed a highly significant correlation with sensory freshness. Loss of moisture, and mould development were main factors for product quality decrease. Better conservation of the product was achieved at 7 °C with a shelf‐life limit of 7 days. At 22 °C, it is recommended to consume the product in 3 days.
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This study was conducted to determine the shelf life of previously frozen pizzas stored at refrigeration temperatures. Pizzas were prepared using meat inoculated with Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium. The pizzas were frozen, then stored at 3 and 10°C. Samples were analyzed every 2 d for 14 d. Sensory analysis was conducted every day for 8 d using uninoculated product. There was a significant (P<0.05) increase in the population of E. coli between 8 and 10 d at 10°C. There were no significant (P>0.05) differences in the populations of S. typhimurium or S. aureus with either time or temperature. The sensory shelf life of the pizzas was approximately 5 d at 10°C and 6 d at 3°C. The pizzas were unacceptable after 7 d at either temperature.
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Most observers have concluded that the introduction into legislation in many countries of the requirement to declare additives in food ingredient lists by functional category and (with the exception of flavourings and modified starches) by their specific name or code number was a crucial and unfavourable influence on consumer attitudes to food additives. While giving consumers the information necessary to make an informed choice, the apparent growth in the list of chemical names, or numbers, on food labels occasioned both surprise and concern. Perversely, a numbering system that had been designed to make it easier for consumers to identify and if they wished, to avoid certain additives, was portrayed as a sinister code to be cracked.
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Mold inhibitors such as sorbates, propionates and benzoates have been used commercially for some time. Recently these and other potential inhibitors have been studied from the standpoint of their effects on growth of potentially toxic molds and mycotoxin production. In addition, other substances such as the antifungal antibiotic natamycin (pimaricin) and plant-derived products such as components of the essential oils of certain herbs and spices have recently been studied for their antifungal properties and effects on mycotoxin production. Some of these inhibitors inhibit mycotoxin production by greater than 70%, while only inhibiting growth of the mold by 25% or less. Of the organic acids, sorbic, propionic and benzoic, sorbic and its sorbate salts seems to be most effective over the widest range of conditions in preventing mold growth and mycotoxin production. Potassium sorbate is effective against toxic molds at levels of 0.10 to 0.15%. The antibiotic natamycin is very effective in preventing mold growt...
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During the last 30 years sorbate has been tested and used widely in the preservation of various food products throughout the world. Currently it has received increased attention as a potential replacer of nitrite for botulism control in processed meat products. Previous reports, however, had suggested sorbate as a selective agent for clostridia in laboratory media. Recent developments as well as the need for safe, practical and effective food preservatives in current and future food processing have generated intense interest in preservatives such as sorbate. This paper reviews the significant developments relating to use of sorbate as a food preservative - its antimicrobial effects, applications, advantages and limitations. A summary of the current status as well as unanswered questions relevant to the mechanism(s) through which the compound exerts its antimicrobial activity also is presented.
Many parameters govern the survival and growth of microorganisms in food. The acidity or pH of a food can affect the type and number of microorganisms present in a product. All microorganisms have minimum, maximum, and optimum pH levels for growth, and altering the hydrogen ion concentration influences the growth or inhibition of an organism. In general, bacteria are more fastidious and prefer to grow at a pH near neutrality (pH 6.5 to 7.5), but they will tolerate a pH range of 4 to 9. Yeasts are more tolerant of lower pH values than bacteria. Molds have the widest range of acceptable pH; foods with a pH below 3.5 can support the growth of both yeasts and molds. Tolerance of organisms to widely differing pH levels varies naturally, and the pH selects the species or group of microorganisms that will predominate in unaltered food products. For example, bacteria primarily spoil proteinaceous foods such as dairy, meat, poultry, and seafoods with a pH range of 5.5 to 6.5. Yeasts and molds more commonly proliferate on fruits and vegetables with inherently lower pH values and little buffering capacity. One effective means of limiting growth is to increase the acidity of a food, thereby creating an unfavorable environment. Adding an acidulant to the food or enhancing natural fermentation to develop acidity changes the pH of the food. These actions tend to be microbiostatic rather than microbiocidal. Success in limiting the numbers of microorganisms will depend on the species of microorganism, the type and concentration of the acidulant, time of exposure, the buffering capacity of the food, and any preexisting conditions in the food that could enhance inhibition. Microorganisms display varied tolerances to acids. For example, the lactic acid bacteria are not only tolerant of weak lipophilic acids but also produce them as a by-product of their metabolism. Some acids, such as acetic acid, are critical to the metabolism of the lactobacilli but inhibitory to bacilli. In mixed flora, the proper use of an acid in a culture medium can select for a particular group. The incorporation of acids into a food can shorten sterilization times for heat treatment owing to the lowered heat resistance of microorganisms in foods with increased acidity. The continued presence of acid can effectively inhibit germination and outgrowth of spores that survive the thermal process. Salt, sugar, and curing agents in conjunction with acids serve to further decrease processing times. Not only would this interaction ensure commercial sterility of the food, but also the decreased processing time would aid in preserving the palatability of the product (Corlett and Brown, 1980). The multiple-barrier concept (“hurdle” concept) has gained popularity for use in a variety of foods in recent years. This concept is based on the premise that foods can be preserved using several inhibitors concurrently rather than relying on a single factor. Therefore, adjustments in pH levels can be coupled with changes in temperature, gaseous atmosphere, water activity, and other inhibitory compounds. The use of the multiple-barrier concept results in lowering the concentrations of acidulants or inhibitors. Comprehensive texts describing applications, physical parameters, and chemical analyses can be found in the references by Ash and Ash (1995) and Doores (2002, 2003).
The ability of modified atmospheres to extend the shelf-life of foods has been recognised for many years. Reports of the use of modified atmospheres date back to the 1920s whilst reports for fish begin in the 1930s (Davis, 1993). Recent years have seen a marked expansion in the use and market share of modified-atmosphere packaging (MAP) generally. This is partly a result of the increasing consumer demand for fresh and chilled convenience foods containing fewer preservatives, which has led to a diversification in the range of products packaged in modified atmospheres. Currently, as well as fish and fish products, foods packaged in MAP include raw and cooked red meats and poultry, fruit and vegetables, fresh pasta, cheese, bakery products, crisps, coffee and tea.
Rope spoilage of bread by Bacillus subtilis and B. licheniformis causes economic losses to the baking industry. The Bacillus spore contamination profile of a typical brown bread manufacturing line in a commercial bakery was assessed by four replicate microbiological surveys to determine numbers, types and sources of Bacillus spores. High Bacillus spore counts were consistently obtained from yeast, crumbs and premix. Food contact surfaces did not contribute noticeably to spore counts. The initial spore count of dough after mixing was 2·6 log cfu g-1 and increased by 0·5 log cfu g-1 before baking. Baking decreased the Bacillus spore count by 1 log cfu g-1. Baked bread stored at 30°C yielded Bacillus counts of c. 107 cfu g-1 after 3 days' storage. Three hundred randomly selected Bacillus isolates from raw materials, dough, food contact surface and bread samples were characterized as 41·5% B. licheniformis, 38·4% B. subtilis, 12·0% B. megaterium, 3·9% B. pumilis, 2·5% B. laterosporus and 1·1% B. cereus.